Ventilated spark-gap.



H. G. FISCHER. VENTILATED SPARK GAP.

' APPLICATION FILED APR. I. 1916- Patented Mar. 26, 1918.

1 sarnrs n c.

HERMAN ('51-.v FISCHER, OFCHICAGO, ILLINOIS, ASSIGNOR OF ONE-HALF T0 HUG-H A.

THOMPSON, 0F LEESBURG, VIRGINIA.

VENTILATED SPARK-GAP.

menses.

Application filed April 1, 1916. Serial N 0. 88,327.

To all whom it may concern Be it known that I, HERMAN G. FISCHER,

I fled in order that the patients being treated may not hear this noise and become nervous and alarmed.

Prior to my invention the sparking device has consisted of a multiple of gaps, each of which is inclosed in a muflier or individual housing, deadening or entirely eliminating the sound. These gaps have, however, been closed to the outside air and it has been found that the amperage of the current has become reduced materially in amount when the apparatus is in continued use, this being due to the change of molecular construction of the air constituents and to the heating of the air particles. My invention contemplates the provision of a muflied multiple spark gap which may be run continuously at an even and readily controlled amperage.

A principal object of this invention is the provlsion ofa multiple spark gap which will be silent, or substantially silent, in operation and which can be relied upon to deliver electrical current of predetermined and uniform characteristics.

Other objects and advantages 'of the invention will be apparent as it is better understood from the following description when considered in connection with the accompanying drawing illustrating a preferred embodiment thereof.

On the drawin Figure lis a slde elevation of a multiple spark gap embodying my invention, parts being broken away to disclose the internal construction;

, Fig. 2 is an end view of the same; and

Fig. 3 is a section taken transversely of the device.

For the purpose of illustrating my Specification of Letters Patent.

end plates 4.

ing 13, 13, each Patented Mar. 26, 11918.

vention I have shown on the drawing a multiple spark gap in which my present inventlon is embodied. On the drawing reference characters 4 represent what may be termed end holding plates which may be of any desired material and which carry three slde bars 5, preferably of glass, fitting 1n sockets 6 appropriately arranged in the The spark gaps indicated at 7 occur between units 8 of any usual material. These units are arranged in alinement and the adjacent ones of two adjacent gaps are connected together by screws 9, the end ones being connected by screws 10 with transverse plates 11 of current conducting material. A similar plate 12 is located upon each screw 9 which connects the adjacent gap elements 8 of adjacent spark gaps. Each gap 7 is inclosed in a two-part houspart 13 being fastened by an appropriate screw 9 between the element and the adjacent plate 11 or 12. These housing parts 13 may also be of current conducting material. The housing parts are insulated from each other by a mica plate 14 forming a partition in the housing. Each plate 14 is provided with a restricted opening 15 about the spark gap proper. The plates 11 and 12 are recessed at two points at 16 to be engaged by appropriate glass connectors 5 and are of dimension causing them to engage the other glass con-1 presses against each end plate 11 and causes the parts to be pressed tightly together through a screw post 19 in threaded 'engagement with an appropriate end plate or member 4. All of the plates 11 and 12 are perforated at 21 for engagement by a connecting rod 22 having an insulated-handle 23, this handle permltting the rod to be pulled in and out to govern the number of spark gaps actually in operation, it being shown in'Fig. 1 as having them all inoperative by reason of the passage of current through the rod 22 instead of across the gaps. So much of the multiple spark gap described has been tested and employed prior to my invention and" it has been air confined in the housings formed by the housing parts 13, 13 that has in the past ininvention I provide communicating apertures or openings 2 L between succeeding housings and stagger these successive apertures with respect to each other. I also provide an opening 25 through the screw posts 19 which, in the present instance, constitutc the binding posts with which the wires of the circuit may be engaged to include the spark device therein. Air is admitted from the right viewing Fig. 1 and passes along the path defined by the arrows and out at the left. In order that this action may be positive I provide a tube 2 -f0r the introduction of compressed air, causing air to be blown continuously through the-tubes when in operation. I have found in the devices in use prior to my invention that the current has dropped within a period of, for example an hour and a half, from 700 milliamperes to approximately 200, and that when air has been forced through in the manner described the efliciency has been unimpaired over a run of several hours, no variation in the current being shown.

It is thought that the invention and many of its attendant advantages will be understood from the foregoing description, and it will be apparent that various changes may be made in the form, construction and arrangement of the parts without departing from the spirit and scope of the invention or sacrificing any of its material advantages,

the form hereinbefore described being merely a preferred embodiment thereof.

1. In an apparatus of the character described the combination of aplurality of connected spark gaps, and individual hous-' ings for the same for the purpose of reduc ing the sound of said sparks, said housings connected spark gaps, individual housings for the same, sald housings having communieating openings staggered with relation to each other for permitting air to pass throu h said housings in a circuitous path.

3. 11 an apparatus of the character described the combination of a spark gap, a housing for the same, a partition in said housing having a restricted aperture through which the spark may pass, and means for forcing air through said housing and through said aperturevacross the gap.

In testimony whereof, I have hereunto set my hand in the presence of two subscribing witnesses.

HERMAN G. FISCHER.

Witnesses:

J. C. CARPENTER, ESTHER ABRAMS. 

